According to Apple, over 100 million apps have been downloaded from the Mac App Store in less than a year. Here’s where things get really interesting — those are unique downloads.

Apple confirmed for me today that those 100 million downloads do not include downloads for its newest operating system OS X Lion. The figure also doesn’t include updates to apps delivered to users from the Mac App Store.

Finally, the figure doesn’t include apps that users downloaded to other authorized Macs. Can you imagine what that figure would be if all of those numbers were included?

Here’s something else to consider. According to market research firm NPD, sales of boxed versions of software in the US reached 50 million copies in the last year.

I’m making a pretty safe assumption that the majority of Apple’s Mac App Store sales come from the US, meaning that Apple is the largest software distributor in the US.